/*
 * FreeRTOS V202212.00
 * Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * https://www.FreeRTOS.org
 * https://github.com/FreeRTOS
 *
 */


/*
 *
 * vMain() is effectively the demo application entry point.  It is called by
 * the main() function generated by the Processor Expert application.
 *
 * vMain() creates all the demo application tasks, then starts the scheduler.
 * The WEB	documentation provides more details of the demo application tasks.
 *
 * Main.c also creates a task called "Check".  This only executes every three
 * seconds but has the highest priority so is guaranteed to get processor time.
 * Its main function is to check that all the other tasks are still operational.
 * Each task (other than the "flash" tasks) maintains a unique count that is
 * incremented each time the task successfully completes its function.  Should
 * any error occur within such a task the count is permanently halted.  The
 * check task inspects the count of each task to ensure it has changed since
 * the last time the check task executed.  If all the count variables have
 * changed all the tasks are still executing error free, and the check task
 * toggles the onboard LED.  Should any task contain an error at any time
 * the LED toggle rate will change from 3 seconds to 500ms.
 *
 * This file also includes the functionality normally implemented within the
 * standard demo application file integer.c.  Due to the limited memory
 * available on the microcontroller the functionality has been included within
 * the idle task hook [vApplicationIdleHook()] - instead of within the usual
 * separate task.  See the documentation within integer.c for the rationale
 * of the integer task functionality.
 *
 *
 *
 * The demo applications included with other FreeRTOS ports make use of the
 * standard ComTest tasks.  These use a loopback connector to transmit and
 * receive RS232 characters between two tasks.  The test is important for two
 * reasons:
 *
 *	1) It tests the mechanism of context switching from within an application
 *	   ISR.
 *
 *	2) It generates some randomised timing.
 *
 * The demo board used to develop this port does not include an RS232 interface
 * so the ComTest tasks could not easily be included.  Instead these two tests
 * are created using a 'Button Push' task.
 *
 * The 'Button Push' task blocks on a queue, waiting for data to arrive.  A
 * simple interrupt routine connected to the PP0 input on the demo board places
 * data in the queue each time the PP0 button is pushed (this button is built
 * onto the demo board).  As the 'Button Push' task is created with a
 * relatively high priority it will unblock and want to execute as soon as data
 * arrives in the queue - resulting in a context switch within the PP0 input
 * ISR.  If the data retrieved from the queue is that expected the 'Button Push'
 * task toggles LED 5.  Therefore correct operation is indicated by the LED
 * toggling each time the PP0 button is pressed.
 *
 * This test is not as satisfactory as the ComTest method - but the simple
 * nature of the port makes is just about adequate.
 *
 */

/* Kernel includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"

/* Demo application includes. */
#include "flash.h"
#include "PollQ.h"
#include "dynamic.h"
#include "partest.h"

/* Processor expert includes. */
#include "ButtonInterrupt.h"

/*-----------------------------------------------------------
 *   Definitions.
 *  -----------------------------------------------------------*/

/* Priorities assigned to demo application tasks. */
#define mainFLASH_PRIORITY          ( tskIDLE_PRIORITY + 2 )
#define mainCHECK_TASK_PRIORITY     ( tskIDLE_PRIORITY + 3 )
#define mainBUTTON_TASK_PRIORITY    ( tskIDLE_PRIORITY + 3 )
#define mainQUEUE_POLL_PRIORITY     ( tskIDLE_PRIORITY + 2 )

/* LED that is toggled by the check task.  The check task periodically checks
 * that all the other tasks are operating without error.  If no errors are found
 * the LED is toggled with mainCHECK_PERIOD frequency.  If an error is found
 * then the toggle rate increases to mainERROR_CHECK_PERIOD. */
#define mainCHECK_TASK_LED          ( 7 )
#define mainCHECK_PERIOD            ( ( TickType_t ) 3000 / portTICK_PERIOD_MS )
#define mainERROR_CHECK_PERIOD      ( ( TickType_t ) 500 / portTICK_PERIOD_MS )

/* LED that is toggled by the button push interrupt. */
#define mainBUTTON_PUSH_LED         ( 5 )

/* The constants used in the idle task calculation. */
#define intgCONST1                  ( ( long ) 123 )
#define intgCONST2                  ( ( long ) 234567 )
#define intgCONST3                  ( ( long ) -3 )
#define intgCONST4                  ( ( long ) 7 )
#define intgEXPECTED_ANSWER         ( ( ( intgCONST1 + intgCONST2 ) * intgCONST3 ) / intgCONST4 )

/* The length of the queue between is button push ISR and the Button Push task
 *  is greater than 1 to account for switch bounces generating multiple inputs. */
#define mainBUTTON_QUEUE_SIZE       6

/*-----------------------------------------------------------
 *   Local functions prototypes.
 *  -----------------------------------------------------------*/

/*
 * The 'Check' task function.  See the explanation at the top of the file.
 */
static void vErrorChecks( void * pvParameters );

/*
 * The 'Button Push' task.  See the explanation at the top of the file.
 */
static void vButtonTask( void * pvParameters );

/*
 * The idle task hook - in which the integer task is implemented.  See the
 * explanation at the top of the file.
 */
void vApplicationIdleHook( void );

/*
 * Checks the unique counts of other tasks to ensure they are still operational.
 */
static long prvCheckOtherTasksAreStillRunning( void );



/*-----------------------------------------------------------
 *   Local variables.
 *  -----------------------------------------------------------*/

/* A few tasks are defined within this file.  This flag is used to indicate
 * their status.  If an error is detected in one of the locally defined tasks then
 * this flag is set to pdTRUE. */
portBASE_TYPE xLocalError = pdFALSE;

/* The queue used to send data from the button push ISR to the Button Push
 * task. */
static QueueHandle_t xButtonQueue;


/*-----------------------------------------------------------*/

/*
 * This is called from the main() function generated by the Processor Expert.
 */
void vMain( void )
{
    /* Start some of the standard demo tasks. */
    vStartLEDFlashTasks( mainFLASH_PRIORITY );
    vStartPolledQueueTasks( mainQUEUE_POLL_PRIORITY );
    vStartDynamicPriorityTasks();

    /* Start the locally defined tasks.  There is also a task implemented as
     * the idle hook. */
    xTaskCreate( vErrorChecks, "Check", configMINIMAL_STACK_SIZE, NULL, mainCHECK_TASK_PRIORITY, NULL );
    xTaskCreate( vButtonTask, "Button", configMINIMAL_STACK_SIZE, NULL, mainBUTTON_TASK_PRIORITY, NULL );

    /* All the tasks have been created - start the scheduler. */
    vTaskStartScheduler();

    /* Should not reach here! */
    for( ; ; )
    {
    }
}
/*-----------------------------------------------------------*/

static void vErrorChecks( void * pvParameters )
{
    TickType_t xDelayPeriod = mainCHECK_PERIOD;
    TickType_t xLastWakeTime;

    /* Initialise xLastWakeTime to ensure the first call to vTaskDelayUntil()
     * functions correctly. */
    xLastWakeTime = xTaskGetTickCount();

    for( ; ; )
    {
        /* Delay until it is time to execute again.  The delay period is
         * shorter following an error. */
        vTaskDelayUntil( &xLastWakeTime, xDelayPeriod );

        /* Check all the demo application tasks are executing without
         * error. If an error is found the delay period is shortened - this
         * has the effect of increasing the flash rate of the 'check' task
         * LED. */
        if( prvCheckOtherTasksAreStillRunning() == pdFAIL )
        {
            /* An error has been detected in one of the tasks - flash faster. */
            xDelayPeriod = mainERROR_CHECK_PERIOD;
        }

        /* Toggle the LED each cycle round. */
        vParTestToggleLED( mainCHECK_TASK_LED );
    }
}
/*-----------------------------------------------------------*/

static long prvCheckOtherTasksAreStillRunning( void )
{
    portBASE_TYPE xAllTasksPassed = pdPASS;

    if( xArePollingQueuesStillRunning() != pdTRUE )
    {
        xAllTasksPassed = pdFAIL;
    }

    if( xAreDynamicPriorityTasksStillRunning() != pdTRUE )
    {
        xAllTasksPassed = pdFAIL;
    }

    /* Also check the status flag for the tasks defined within this function. */
    if( xLocalError != pdFALSE )
    {
        xAllTasksPassed = pdFAIL;
    }

    return xAllTasksPassed;
}
/*-----------------------------------------------------------*/

void vApplicationIdleHook( void )
{
/* This variable is effectively set to a constant so it is made volatile to
 * ensure the compiler does not just get rid of it. */
    volatile long lValue;

    /* Keep performing a calculation and checking the result against a constant. */
    for( ; ; )
    {
        /* Perform the calculation.  This will store partial value in
         * registers, resulting in a good test of the context switch mechanism. */
        lValue = intgCONST1;
        lValue += intgCONST2;
        lValue *= intgCONST3;
        lValue /= intgCONST4;

        /* Did we perform the calculation correctly with no corruption? */
        if( lValue != intgEXPECTED_ANSWER )
        {
            /* Error! */
            portENTER_CRITICAL();
            xLocalError = pdTRUE;
            portEXIT_CRITICAL();
        }

        /* Yield in case cooperative scheduling is being used. */
        #if configUSE_PREEMPTION == 0
        {
            taskYIELD();
        }
        #endif
    }
}
/*-----------------------------------------------------------*/

static void vButtonTask( void * pvParameters )
{
    unsigned portBASE_TYPE uxExpected = 1, uxReceived;

    /* Create the queue used by the producer and consumer. */
    xButtonQueue = xQueueCreate( mainBUTTON_QUEUE_SIZE, ( unsigned portBASE_TYPE ) sizeof( unsigned portBASE_TYPE ) );

    if( xButtonQueue )
    {
        /* Now the queue is created it is safe to enable the button interrupt. */
        ButtonInterrupt_Enable();

        for( ; ; )
        {
            /* Simply wait for data to arrive from the button push interrupt. */
            if( xQueueReceive( xButtonQueue, &uxReceived, portMAX_DELAY ) == pdPASS )
            {
                /* Was the data we received that expected? */
                if( uxReceived != uxExpected )
                {
                    /* Error! */
                    portENTER_CRITICAL();
                    xLocalError = pdTRUE;
                    portEXIT_CRITICAL();
                }
                else
                {
                    /* Toggle the LED for every successful push. */
                    vParTestToggleLED( mainBUTTON_PUSH_LED );
                }

                uxExpected++;
            }
        }
    }

    /* Will only get here if the queue could not be created. */
    for( ; ; )
    {
    }
}
/*-----------------------------------------------------------*/

#pragma CODE_SEG __NEAR_SEG NON_BANKED

/* Button push ISR. */
void interrupt vButtonPush( void )
{
    static unsigned portBASE_TYPE uxValToSend = 0;
    static unsigned long xHigherPriorityTaskWoken;

    xHigherPriorityTaskWoken = pdFALSE;

    /* Send an incrementing value to the button push task each run. */
    uxValToSend++;

    /* Clear the interrupt flag. */
    PIFP = 1;

    /* Send the incremented value down the queue.  The button push task is
     * blocked waiting for the data.  As the button push task is high priority
     * it will wake and a context switch should be performed before leaving
     * the ISR. */
    xQueueSendFromISR( xButtonQueue, &uxValToSend, &xHigherPriorityTaskWoken );

    if( xHigherPriorityTaskWoken )
    {
        /* NOTE: This macro can only be used if there are no local
         * variables defined.  This function uses a static variable so it's
         * use is permitted.  If the variable were not static portYIELD()
         * would have to be used in it's place. */
        portTASK_SWITCH_FROM_ISR();
    }
}

#pragma CODE_SEG DEFAULT
